freegroup.de spindle idle

// hello, stranger.

I build things
that build things.

Developer by heart, maker by hand. Software is great — software that makes hardware move is better. Circuit simulators, diagram engines, CNC toolpaths and a respectable number of blinking LEDs.

JOB hello.nc X 0.00 Y 0.00 Z 5.00
01

The heart project

A digital circuit with logic gates and flip-flops in Electra Academy
♥ HEART PROJECT

Electra Academy

You understand circuits by building them.

A free platform for digital electronics: drag gates onto the canvas, wire them up and watch the current flow. When something doesn't work, you see why. No account, no install, free for schools.

  • Simulatorbuild · simulate · understand
  • Authorlessons, worksheets, flip cards
  • Designeryour own parts, in a few lines of JS
Open Electra Academy
02

Fresh off the mill

NEW · 2026

PatternMaster

Wood in. Pattern out.

Pick a pattern — diamonds, waves, honeycomb — nudge a few sliders and see the milled workpiece in 3D before a single chip flies. PatternMaster computes the toolpaths, you press start. Runs in the browser. No install, no account.

  • CNC
  • 3D preview
  • Toolpaths
  • Browser
Open PatternMaster
PatternMaster showing a 3D preview of a diamond pattern milled into wood
03

From the workshop

New toys and old builds. Still running. Mostly.

A-01 NEW

8-Bit CSS Icon Builder

Paint pixel icons, get pure CSS back — one element, a pile of box-shadows. The invader above is made exactly that way.

  • Pixel art
  • CSS
  • Editor
A-02

Camping Calc

Will the battery survive the weekend? Power budgeting for your camping trip, before the fridge goes quiet.

  • PWA
  • Vue
  • Utility
A-03

Draw2D

A JavaScript library for flowcharts, diagrams and anything made of boxes and lines.

  • Library
  • JavaScript
  • SVG
A-04

HoruCNC

Turns images into G-code for CNC milling. PatternMaster's older, grumpier sibling.

  • CNC
  • G-Code
  • GRBL
A-05

Eagle Viewer

Renders Eagle PCB files right in the browser. Built to understand the format, kept because it's fast.

  • PCB
  • Parser
  • WebGL
A-06

DigitalSimulator

A digital logic simulator for Windows: drop gates and flip-flops, wire them up, watch the bits flow. C++ with Java bindings, from the CRT era.

  • Windows
  • C++
  • Logic
Draw2D DHTML - Microsoft Internet Explorer
The original Draw2D DHTML port demo: green figures connected by lines
Fig. 1 — the real demo. Still running.
A-07 · MUSEUM

Draw2D DHTML

Where it all began, ~20 years ago.

No <canvas>. No SVG you could rely on. So how do you draw a line in a browser? You place one tiny <div> for every single pixel. Curves, connections, shapes, drag & drop — all of it. Fig. 2 is drawn exactly that way, right here in your browser.

And yes: it still runs. Go click through the demos.

Open the demos >>
04

About the operator

Hardware and software — that's where my heart is. Especially the spot where one makes the other move.

I don't just write code: I build solutions, automate the boring stuff and bring ideas to life. From backend systems to logic gates, from G-code to 3D printing — if it compiles, clicks, blinks or spins, I'm probably tinkering with it.

Everything here is non-profit and open source. Built because it was fun, shared because it might be useful to someone.

Find the source on GitHub →

BILL OF MATERIALSREV 2026
#PartNotes
01Full Stackfrom pixel to packet
02Node.jsdaily driver
03Pythonduct tape for the universe
04ML / AIteaching rocks to think
05K8s & Dockercontainers all the way down
06Cloud (GCP/AWS)someone else's computer
07Arduinoblinks LEDs professionally
083D Printingspaghetti, occasionally parts